Astronomy:45 Eridani

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Short description: Star in the constellation Eridanus
45 Eridani
Observation data
Equinox J2000.0]] (ICRS)
Constellation Eridanus
Right ascension  04h 31m 52.66831s[1]
Declination −00° 02′ 38.4407″[1]
Apparent magnitude (V) 4.91[2]
Characteristics
Evolutionary stage giant
Spectral type K0/1 III[3]
U−B color index +1.41[4]
B−V color index +1.32±0.04[2]
Astrometry
Radial velocity (Rv)+15.22±0.35[1] km/s
Proper motion (μ) RA: −1.149[1] mas/yr
Dec.: −7.655[1] mas/yr
Parallax (π)4.6579 ± 0.2082[1] mas
Distance700 ± 30 ly
(215 ± 10 pc)
Absolute magnitude (MV)−1.59[2]
Details
Radius50.06±1.73[1] R
Luminosity787.9±40.1[1] L
Surface gravity (log g)2.0[5] cgs
Temperature4322+58
−57
[1] K
Metallicity [Fe/H]−0.17[5] dex
Other designations
45 Eri, BD−00°713, GC 5528, HD 28749, HIP 21139, HR 1437, SAO 131270[6]
Database references
SIMBADdata

45 Eridani is a single[7] star located around 700 light years away from the Sun in the equatorial constellation of Eridanus. It is visible to the naked eye as a faint, orange-hued star with an apparent visual magnitude of 4.91.[2] This body is moving away from the Earth with a heliocentric radial velocity of +15 km/s.[1]

The stellar classification for this star is K0/1 III,[3] which indicates this is an aging K-type giant star that has exhausted the hydrogen supply at its core and expanded. It has reached 50[1] times the Sun's radius and is radiating 788[1] times the luminosity of the Sun from its swollen photosphere at an effective temperature of 4,322 K.[1]

References

  1. 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. 2.0 2.1 2.2 2.3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters 38 (5): 331. doi:10.1134/S1063773712050015. Bibcode2012AstL...38..331A. 
  3. 3.0 3.1 Houk, N.; Swift, C. (1999). "Michigan catalogue of two-dimensional spectral types for the HD Stars". Michigan Spectral Survey 5. Bibcode1999MSS...C05....0H. 
  4. Mermilliod, J.-C. (1986). "Compilation of Eggen's UBV data, transformed to UBV (unpublished)". Catalogue of Eggen's UBV Data. Bibcode1986EgUBV........0M. 
  5. 5.0 5.1 McWilliam, Andrew (December 1990). "High-resolution spectroscopic survey of 671 GK giants. I - Stellar atmosphere parameters and abundances". Astrophysical Journal Supplement Series 74: 1075–1128. doi:10.1086/191527. Bibcode1990ApJS...74.1075M. 
  6. "45 Eri". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=45+Eri. 
  7. Eggleton, P. P.; Tokovinin, A. A. (September 2008). "A catalogue of multiplicity among bright stellar systems". Monthly Notices of the Royal Astronomical Society 389 (2): 869–879. doi:10.1111/j.1365-2966.2008.13596.x. Bibcode2008MNRAS.389..869E.